BackgroundWorker.IsBusy Propriedade

public:
 property bool IsBusy { bool get(); };

public bool IsBusy { get; }

[System.ComponentModel.Browsable(false)]
public bool IsBusy { get; }

member this.IsBusy : bool

[<System.ComponentModel.Browsable(false)>]
member this.IsBusy : bool

Public ReadOnly Property IsBusy As Boolean

Valor de Propriedade

true, se o BackgroundWorker estiver a executar uma operação assíncrona; caso contrário, false.

Atributos

BrowsableAttribute

Exemplos

O seguinte exemplo de código demonstra como usar a IsBusy propriedade para esperar pela conclusão de uma BackgroundWorker operação. Este exemplo de código faz parte de um exemplo mais amplo descrito em Como: Descarregar um Ficheiro em Segundo Plano.

void downloadButton_Click(object sender, EventArgs e)
{
    // Start the download operation in the background.
    backgroundWorker1.RunWorkerAsync();

    // Disable the button for the duration of the download.
    downloadButton.Enabled = false;

    // Once you have started the background thread you
    // can exit the handler and the application will
    // wait until the RunWorkerCompleted event is raised.

    // Or if you want to do something else in the main thread,
    // such as update a progress bar, you can do so in a loop
    // while checking IsBusy to see if the background task is
    // still running.

    while (backgroundWorker1.IsBusy)
    {
        progressBar1.Increment(1);
        // Keep UI messages moving, so the form remains
        // responsive during the asynchronous operation.
        Application.DoEvents();
    }
}

Private Sub downloadButton_Click( _
    ByVal sender As Object, _
    ByVal e As EventArgs) _
    Handles downloadButton.Click

    ' Start the download operation in the background.
    Me.backgroundWorker1.RunWorkerAsync()

    ' Disable the button for the duration of the download.
    Me.downloadButton.Enabled = False

    ' Once you have started the background thread you 
    ' can exit the handler and the application will 
    ' wait until the RunWorkerCompleted event is raised.

    ' If you want to do something else in the main thread,
    ' such as update a progress bar, you can do so in a loop 
    ' while checking IsBusy to see if the background task is
    ' still running.
    While Me.backgroundWorker1.IsBusy
        progressBar1.Increment(1)
        ' Keep UI messages moving, so the form remains 
        ' responsive during the asynchronous operation.
        Application.DoEvents()
    End While
End Sub

Observações

Inicia BackgroundWorker uma operação assíncrona quando chama RunWorkerAsync.

Ver também

• RunWorkerCompleted
• EventArgs
• RunWorkerAsync
• Como: Executar uma operação em segundo plano
• Como: Baixar um arquivo em segundo plano